This trial involves 300 patients from 15 centers (20 patients per site) and is a placebo-controlled, dose-ranging, randomized study aimed at investigating both safety and efficacy of three different doses of oral propionly l-carnitine hydrochloride (PLC-HCL) in patients with intermittent claudication. Efficacy will be assessed by evaluating maximal walking distance on a standardized treadmill after six months of double-blind treatment.